Sewing machine for stitching leather cases



Sept. 15, 1953 J. HEGGIE SEWING MACHINE FOR STITCHING LEATHER CASES 4 Sheets-Sheet l Filed June 27, 1951 James By r/zs HTToRNEy 'Sept; "15,1953" J. HEGGIE SEWING MACHINE FOR STITCHING LEATHER CASES 4 Sheets-Sheet 2 Filed June 27, 1951 K/zJsFrraer/sy Sept. 15, 1953 J. HEGGIE SEWING MACHINE FOR STITCHING LEATHER CASES 4 Sheets-Sheet 5 Filed June 27, 1951 Sept. 15, 1953 J. HEGGIE 2,552,014

I SEWING MACHINE FOR STITCHING LEATHER CASES Filed June 27, 1951 -4 Sheets-Sheet 4 MME/Ww/E 5 James QieyyiQ Patented Sept. 15, 1953 SEWING MACHINE FOR STITCHING LEATHER CASES James Heggie, Clydebank, Scotland, assignor to The Singer Manufacturing Company, Elizabeth, N. J a corporation of New Jersey Application June 27, 1951, Serial No. 233,734 In Great Britain June 30, 1950 Claims.

This invention relates to sewing machines for stitching leather cases and of the type described in the prior U. S. Patent No. 2,489,489 dated November 29, 1949, for stitching diagonally through the sides or panels of leather cases along the line of abutment of sheets or strips disposed approximately perpendicularly to one another.

The present invention provides a sewing machine of the type embodying improved work retaining and guiding means which, by a simple replacement of one part, render it practicable to use the sewing machine either for stitching straight work pieces or for stitching curved or kidney-shaped work pieces while using a. straight needle.

A sewing machine to which the invention is applied has a work arm in which are mounted a shuttle-operating shaft and a pusher-operating shaft as described in the said patent, an inclined throat plate at the free end of the work arm, an abutment member mounted on said throat plate, a reciprocatory needle feed driver mounted on the pusher-operating shaft and extending into the needle path, and a work retainer mounted adjustably relatively to a bracket secured at one end to the work arm.

The invention will now be described with reference to the accompanying drawings, in which only so much of a sewing machine is shown as is necessary for a clear understanding of the invention.

In the drawings Fig. 1 is a fragmentary view partly in side elevation and partly in section of one construction according to the invention; Fig. 2 is a plan of Fig. 1; Fig. 3 is a side elevation showing part of a sewing machine with the invention in its preferred form applied thereto; Fig. 4 is a front view of part of Fig. 3 looking in the direction of the arrow A, Fig. 3; Fig. 5 is a plan view of part of Fig. 3 looking in the direction of the arrow B. Fig. 3; Fig. 6 is a side view partly in section of part of Fig. 3; Fig. '7 is a front view and Fig. 8 a side view of a guide plate removed from the machine and showing the construction of guide plate used when sewing straight work; Fig. 9 is a front view and Fig. 10 a side view of a form of guide plate used for sewing curved or kidney-shaped work; Fig. 11 is a front view; Fig. 12 a side view and Fig. 13 a plan of a needle feed driver shown removed from the machine; Fig. 14 is a fragmentary side elevation showing the operation of the work retainer.

The same reference characters indicate corresponding parts in the several figures of the drawings- Referring to Fig. 1, It indicates the upper end of an inclined work retainer carrying at its upper extremity a roller ll rotatable about an axis l2 perpendicular to the longitudinal axis of the work retainer and bearing on the leather or like strip X pressed against the abutment member or guide plate it. The guide plate 13 is formed on its outer face with a concavity l3 with which the normally plane leather strip abutting thereon is caused to conform to bring the edge portions to be united well within the range of the needle path.

On the inner or opposite side of the abutment l3 there is supported on the throat plate It a block [5 carrying a needle guide in the form of a roller It the axis [1 of which is parallel to the axis :2, said roller is resisting backward yield: ing movement of the straight needle I8, under pressure of the work piece. The throat plate [4 is carried on the work arm of the machine indicated in dotted lines at W.

Referring to the constructions shown in Figs. 3, 4 and 5, a mushroom-headed thimble i9 is rotatably mounted on the upper end of the work retainer. This thimble, while holding the work piece X firmly against the abutment plate or guide plate 32 during the stitching operation, permits the work piece to be moved freely along said plate.

'20 indicates the throat plate which is removably mounted on a base plate 2| attached to the free end of the work arm W of the machine.

The throat plate '20 is of arcuate section and is cut away at its rear edge to provide an opening for passage of a reciprocatory needle feed driver.

The throat plate 26 is also formed with a slot 25 for passage of the needle and forming a needle throat.

The needle feed driver movable transversely of the work-arm comprises a vertical arm 26 and a horizontal arm 21 extending therefrom approximately mid-way of its height.

The vertical arm 26 is secured at its lower end by a screw to a feed-rock shaft 28, and projects upwardly through the cut-away in the throat plate 26 while the horizontal arm 21 extends below the throat plate 20, and is formed with a needle slot 2'! and with an upstanding projection 29 adapted to enter the slot '25 in the guide plate 28 to afford guide means and to provide means for imparting lateralmovement to the needle E8 in one direction.

Secured to the top of the vertical arm 2 5 is a finger 39 which extends above the throat plate 20 and is formed at its extremity with a projecting tip 35 extending close to the path of the needle 18 on the opposite side of the needle l8 from the projection 29.

Referring particularly to Figs. 4, and 6, the operation of the needle-feed device is readily apparent. As the needle 18 moves downward, it passes to the right of the finger tip 3| and to the left of the projection 29, as viewed in Fig. 4. When the point of the needle [8 extends through the work material below the projection 29, the needle feed driver arm 26 is timed to rock counterclockwise, as viewed in Fig. 4, and carry the needle [8, and therefore the work material, to the left a predetermined distance which is the length of one stitch. The feed drive mechanism is also timed to cause the arm 26 to rock clockwise as soon as the needle l8 rises clear of the work material. Upon clockwise motion of the arm 25, the finger tip 3| engages the needle l8, carrying it in the opposite direction to that imparted by the projection 23 to the correct position to start a new stitch.

An abutment member or guide plate 32 is formed by a bracket member adapted for attachment to the throat plate 26 with provision for adjustment relatively thereto and for locking said guide plate 3?. in its position of adjustment.

The bracket member is formed with extensions 33, 34 perpendicular to the throat plate 23 and spaced apart to provide an opening 36 for passage of the finger 30.

One edge 33 of said opening 36 is chamfered inwardly and the opposite edge 36 is inclined. When the machine is to be used for stitching straight work strips, the bracket member as shown in Figs. '7 and 8, is formed with horizontal extensions 31, 38 projecting at right angles to the extensions 33, 34, said extensions 3'1, 38 each being curved on its underside to conform with the curvature of the throat plate 20 and on its upper face formed with a plane surface, the two plane surfaces of the extensions .37, 38 in conjunction with the central part of the curved throat plate 28 providing a guide surface for a straight work piece which is held on said surface by the operator.

When the machine is to be used for stitching curved work pieces, the bracket member 32, which is itself formed on its underside to fit the throat plate 2!] does not have the forwardly extending extensions.

Figs. 9 and illustrate this latter form of bracket member and parts corresponding to those shown in Figs. 7 and 8 are indicated by the same reference characters distinguished by the addition of the exponent The abutment 32 is adjustably secured to the throat plate 23 by screws 39 passing through slots 40, see Fig. 5.

To permit of lateral adjustment of the abutment 32, the latter is furnished with a screw 4| threaded into the abutment and provided with a head 42 and a collar 43. The screw 4| is engaged in a slotted member 44 on the throat plate whereby to anchor said screw, rotation of the screw 41 serving to move the abutment 32 towards or away from the front edge of the throat plate 23.

The opening 36 ensures that the leather being stitched is maintained in correct position for penetration by the needle Ill, the particular portion of the leather being forced or bulged outwards by the work retainer during the stitching operation.

The position of the work retainer is adjustable to ensure that the bottom leather is gripped on the horizontal guide plate while the top leather is inserted in correct relation to the lower leather for stitching, and to control the top leather to regulate the position of the line of stitching, the line of stitches in the top leather being spaced at a distance from the edge of the top leather greater than the distance of the line of stitches on the bottom leather, which should be as close as possible to the edge of the said leather compatible with security.

The work retainer H] which may be in the form of a straight rod as shown in Fig. 14, is fitted in a sleeve 45 adjustable in a bracket 45 releasably clamped. to a cross-member 41 carried by the horizontal arm of a substantially T-shaped bracket 48, the vertical leg of which is secured to a vertical post 49 attached at its lower end to a floor plate while the end of the horizontal arm remote from the work retainer is provided with means indicated at 49 whereby it may be clamped to the work arm W of the sewing machine.

Pivoted adjacent to the bracket 46 is a hooked member 50 adapted to engage said bracket to retain it in position when the work-retainer has been moved into operative position by depression of a treadle not shown.

Pivoted on the vertical leg of the cross-member 48 is a bell-crank lever 5|, the longer arm of which is adapted to make contact with the proximal end of the work retainer I!) through the medium of an adjustable screw 52, while the shorter arm is in operative association with a treadle through the medium of a rod 53 furnished at its upper end with a spring 54 the stress of which is adjustable by manipulation of a nut 55, and at its lower end connected to a treadle.

The needle I8 is of the flattened or spearpointed type whereby to facilitate penetration of the leather during the stitching operation.

The needle 3 is held in a holder l8 which is pivotally connected to a bracket I8 clamped to the needle-bar.

The provision of the revoluble thimble on the end of the Work retainer It renders it possible for the operator to hold the lowermost piece of leather on the guide plate 20 while permitting the upper leather to be slid into correct position relatively to the lower leather, the thimble rotating freely about the work-retaining arm to facilitate passage of the upper leather while still maintaining a grip on the lower leather. With the two leathers in correct position for stitching, the operator presses the starting pedal to begin the stitching operation and then guides the leathers in the desired direction, the revoluble thimble permitting free movement of the leather work-pieces while holdin them firmly against the guide plate and abutment member.

What is claimed is:

1. In a machine for stitching leather cases and the like, the combination with a machine frame including a horizontal work-arm, a vertically reciprocatory and laterally movable needle, a throat-plate disposed at the free end of said work-arm, and presenting a needle thread, a needle feed driver movable in the direction transverse to said Work-arm, said needle feed driver including a vertical arm and a horizontal arm formed with a needle slot and having a part entering said needle throat and a projecting part at one side of the needle, a part projecting from said vertical arm and having a projecting tip on the other side of the needle from said first mentioned projecting part, means for rocking said needle driver to impart oppositely directed lateral movements to the needle by way of said projecting parts.

2. In a machine for stitching leather cases and the like, the combination with a machine frame including a horizontal work-arm, a vertically reciprocatory and laterally movable needle, a throat-plate of arcuate section disposed at the free end of said work-arm, and presenting a needle-throat, a needle feed driver movable in the direction transverse to said workarm, said needle feed driver including a vertical arm and a horizontal arm formed with a needle slot and with a part entering said needle-throat, and with a projection at one side of the needle, a finger on said vertical arm having a projecting tip on the other side of the needle from said projection, means for rocking said needle driver to impart oppositely directed lateral movements to the needle by way of said finger and said projection, a work-guiding abutment member disposed above said throat-plate, and provided with extensions presenting plane work-supporting surfaces extending on either side of said projecting tip and provided with an opening through which said tip passes, and a Work-retainer for urging a work-piece towards said projecting tip and said abutment member.

3. In a machine for stitching leather cases and the like, the combination with a machine frame including a horizontal work-arm, a vertically reciprocatory and laterally movable needle, a throat-plate of arcuate section disposed at the free end of said work-arm and presenting a needle-throat, a needle feed driver movable in the direction transverse to said workarm, said needle feed driver having a vertical arm and a horizontal arm formed with a needle slot, with a part entering said needle-throat, and with a projection at one side of the needle, a part on said vertical arm having a projection on the other side of the needle from said first mentioned projection, means for rocking said needle driver to impart oppositely directed lateral movements to the needle by way of said projections.

4. In a machine for stitching leather cases and the like, the combination with a frame including a horizontal work-arm, a vertically reciprocatory and laterally movable needle, a throat-plate disposed at the free end of said work-arm and presenting a needle-throat, a work-guiding abutment member mounted on said throat plate and having a work-supporting face adjacent said needle, said face having a concavity formed therein adjacent said needle, and a work-retainer for urging a work-piece in the direction into the cavity in said abutment member, said Work retainer including a roller rotatable about an axis parallel to said outer face of said abutment member.

5. In a machine for stitching leather cases and the like, the combination with a machine frame including a work-arm, a reciprocatory and laterally movable needle, a throat-plate carried by said work-arm and provided with a needle throat, a rockable needle feed driver movable in a direction transverse to said work arm, said needle feed driver including a vertical arm and a horizontal arm, said horizontal arm having a needle slot and a projecting part at one side of said needle, a second part projecting from said vertical arm and having a projecting tip on the other side of said needle from said first mentioned projecting part, means for rocking said needle driver, a work-guiding abutment member fastened to said throat-plate and having a workengaging face provided with an opening adjacent said needle, and a work retaining roller having an axis of rotation parallel to said work engaging face for engaging work material.

JAMES HEGGIE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,265,448 Hess May 7, 1918 2,489,489 Heggie Nov. 29, 1949 

